Since the early days of SCUBA (Self-Contained Underwater Breathing Apparatus) diving, communication between SCUBA divers has been an issue. This is due to the fact that the use of the SCUBA includes a mouthpiece worn by the divers which precludes direct voice communication. However, because of the risks involved in an underwater environment, divers have a critical need to communicate a variety of safety related messages to their fellow divers, e.g., communicating the amount of air they have remaining. As a result, a series of hand signs have been developed for underwater communication, but they only cover a very limited number of messages and cannot quickly get other divers' attention in critical situations. Various underwater graphical display devices have also been developed, but they have the same limitation as the hand signs. Furthermore, these devices which are worn on the diver's wrist or arm require the diver to divert his or her attention from what they are doing to look at the display. However, divers typically dive with their heads up to watch for their directions and with their arms besides their torsos to reduce the water resistance. Henceforth, the diver's natural diving position is not conducive to monitoring a visual alert on their wrist or elsewhere (e.g., arm or waist). This is even true for visual alerts being projected on the diver's face mask since the diver's attention is more focused on what is in front of them and not on what is projected on his or her face mask.
Acoustic alarm systems have also been developed, but they are code-based instead of voice-based. Therefore, such system can only communicate a limited number of messages and require the diver to understand their individual codes. Also, none of these devices provide for communication between divers and a surface craft such as a dive boat (a boat which transports and supports the divers). Further, none of these devices provides for communication between divers who are not in very close proximity. Thus, there is a need for an apparatus and an approach allowing for voice-based alerts to be communicated to the divers, for voice communication between divers while they are underwater, as well as for voice communication between divers and the surface craft.